The present application is generally related to inground operations and, more particularly, to a system, apparatus and method for electromagnetically coupling an electrical signal onto an electrically conductive drill string to produce a corresponding electrical signal on the drill string.
Generally, an inground operation such as, for example, drilling to form a borehole, subsequent reaming of a borehole for purposes of installing a utility line, borehole mapping and the like use an electrically conductive drill string which extends from an above ground drill rig. The prior art includes examples of the use of an electrically conductive drill string as an electrical conductor for serving to electrically conduct a data signal from an inground tool to the drill rig. The surrounding earth itself serves as a signal return path for purposes of detecting the signal at the drill rig. This type of system is often referred to as a measurement while drilling, MWD, system. Applicants recognize, however, that that there remains a need for improvement in MWD systems.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.